Coaxial cables or traces are commonly used to carry radio signals, video signals, measurement and data signals, and the like. A typical coaxial cable comprises two conductive channels arranged along a single axis and separated by a layer of insulating material. The conductive channels and the insulating layer are enclosed within a second insulating layer. Typically, the inner conductive layer carries the signal and the outer conductive layer serves as a grounding layer.
In semiconductor applications signals must often be shielded so they do not interfere with separate transmissions or other activities taking place elsewhere. Coaxial traces are ideal, and often required, for transmitting shielded signals, yet no method for manufacturing coaxial cable within semiconducting substrates currently exists. Signal transmission in semiconductors is presently accomplished using bulky wiring solutions external to the silicon or other semiconducting material. Signal traces embedded in a semiconducting substrate would be less bulky and would be well suited to stackable packaging solutions. Accordingly, there exists a need for a method of manufacturing signal traces, including coaxial traces, within a semiconducting or other surrounding material.
For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the invention. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention. The same reference numerals in different figures denote the same elements.
The terms “first,” “second,” “third,” “fourth,” and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms “comprise,” “include,” “have,” and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
The terms “left,” “right,” “front,” “back,” “top,” “bottom,” “over,” “under,” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein. The term “coupled,” as used herein, is defined as directly or indirectly connected in an electrical or non-electrical manner.